SU894170A1 - Core bit - Google Patents

Description

(54) COLUMN CHAIN

one

The invention relates to a rock cutting tool for coring, namely core cone bits.

The core roller bit is known, which includes a housing with inclined trunnions cut to the borehole walls, on which the cones are mounted by bearings in the form of a part of a truncated sphere whose radius is equal to the radius of the borehole 1.

A disadvantage of the known drill bit is the low mechanical speed of drilling due to the large contact surface of the roller cone armature with the bottom hole.

The closest to the proposed for technical sushi, nosti and the achieved result is a coring bit, containing a housing with axles from the center to the periphery, on which the cones are mounted by means of bearings, made in the form of a part of a truncated sphere relative to the axis of symmetry of the bit 2.

A disadvantage of the known chisel is the low efficiency of rock destruction. This is due to the fact that when drilling from all the cones, the trajectories coincide with each other, which leads to the formation of a slat at the bottom and a decrease in the efficiency of the destruction of the bottom.

The purpose of the invention is to increase the efficiency of rock destruction by increasing the contact pressure while at the same time eliminating the formation of a slat at the bottom of a well.

The goal is achieved by the fact that at least two cutters are made with

ig mutually opposite offset.

FIG. 1 shows the core bit, a general view in section (section BB in Fig. 2); in fig. 2 is a schematic of the arrangement of the slings in the plan and the direction of displacement of their axes (view A in FIG. 1); in fig. 3-6 - we defeat the bottom, respectively, when installing the cones in the chisel with positive, negative, zero, and asymmetric blends.

Claims (2)

The bit consists of body 1, on three pins 2 of which, by means of bearings, 3 are mounted cones 4-6, armed with carbide teeth 7. All cones 4-6 are made in the form of a truncated sphere, the surface of which is formed by radius R equal to the radius of the well. In Chisel, roller cutter 4 has a negative mixing (-K) of its axis relative to the axis of the bit, roller cutter 5 - positive (+ KJ, and roller cutter 6 has zero mixing. Absolute mixing values (k) can be different. This design of the bit causes during its operation, the teeth 7 of one roller cutter slide along the rock in the direction from the center to the periphery, the teeth of the other from the periphery to the center, and the teeth of the third roller cutter slide: running from the periphery to the center, and running away from the center to the periphery. tooth trajectories s on the surface of the spherical slab mutually intersect (Fig. 6). The trajectories of cones 4 with negative mixing do not coincide with the trajectories from cones 5 with positive displacement, and the trajectories from these both consoles 6 do not coincide with the trajectories of cones 6 with zero offset. the bit excludes the formation of a bottom slat, which together with an increase in the contact pressure on the rock leads to an increase in drilling efficiency. Formula of the invention Core bit, containing body with axles cut from center to periphery, on which roller bearings are mounted by means of bearings, made in the shape of a part of a truncated sphere and installed with mixing of their axes relative to the axis of symmetry of the bit, characterized in that by increasing the contact pressure while at the same time eliminating the formation at the bottom of the rail, at least two cones are made with mutually opposite mixing. Sources of information taken into account during the examination 1. USSR author's certificate No. 259756, cl. E 21 B 9/18, 1960. 2. Drill heads for percussion devices. GOST 21210-75, p. 2, trait 1 (prototype).  // x- / /// - /// /   / // / /. /. / / / /////////// / V V V V V V V V V 9 / / b ig.5 h (PU2.S